Semiautomatic train control



March 31, "1925.

L. E. DODGE TmU m z E 5 M iv L 9 l SEMIAUTOMATIC TRAIN CONTROL Original Filed March 21 INVEN TOR March '31, 1925.

1 L. E. DODGE SEMIAUTOMATIC TRAIN CONTROL Original Filed March 21 '1922 2 Sheets-Sheet 2 YLHWM was INVENTOR 2W Patented Mar. 31, i925.

SEMIAUTOMATIC TRAIN CO'ZITRQL.

Application filed Iriarch 21, 1922, Serial To all w/mm it may concern:

Be it known that I, LYMAN E. Donor), a citizen of the United States, and a resident of the city of Morristown, in the county of Morris and State of New Jersey, have invented a new and useful semiautomatic Train Control, of which the following is a specification.

This invention relates -to automatic train control and more especially to a. system of automatic train control in which it is necessary for the train driver to take appropriate action whenever the train passes an indication point on the roadway, and for that reason has been denominated by me a semiautomatic train control.

The principal object of this invention is the production of a train control system which will so act that it will operate to impose a gradually decreasing maximum permissible speed on the train after passing an indication point inthe roadway, whether or not the indication from the roadway is equivalent to a full clear signal or a caution signal unless the train driver at the appropriate moment performs a manual operation on the train, so that even if the equipped vehicle passes an indication on the traclc way, which would be equivalent to a full clear signal on the train, if properly accepted by a manual operation of the engine driver, nevertheless, if this manual operation is not performed, the train will be brought to a stop before proceeding so far as to cause a collision, as for instance with a train ahead.

it is also an object of this invention to provide a system by which the driver, after a caution signal has been passed. or when e has approached to within a substantially maximum braking distance from a preceding' train will be obliged to gradually decrease the speed of the train. so that it will be brought to a stop or a minimum low speed before reaching the danger point ahead, or upon his failure to so do, to cause an automatic application of the'air brakes of the train. p

A further object of the invention is to provide a system such that the driver while gradually reducing speed in obedience to a caution signal, must at appropriate times perform manual operations, and upon his failure so to do, then the system is so designed that the air brakes will he applied regardless of the speed of the train.

No. 545,564. Renewed January 9, 1925.

as the description of the particular physical embodiment selected to illustrate theinvention progresses, and the novel features of the invention will be particularly pointed out in the appended claims.

In describing the invention in detail, and the particular physical embodiment selected to illustrate the invention, reference is had to the accompanying drawings, wherein I have illustrated a particular preferred physical embodiment of my invention, and wherein like characters of reference designate corresponding parts throughout the several views, and in which:

Fig. 1 somewhat conventional track and associated signals to which the trackway portion of my invention has been applied;

Fig. 2 is a schematic illustration of the mechanism required by my invention as positioned upon a movable vehicle;

Fig. 3 is a fragmentary sketch of a detail as shown by Fig. 2;

Fig. 4 is a fragmentary sketch'of a detail as shown by Fig. 2.

is a schematic illustration'of a Referring particularly to Fig. 1, numerals 4 skilled in the railway signalling art, andin the diagram I have shown them in such positions that when signal 7 is at danger as shown, then signal 6 is at cautiona nd signal 5 is at full clear, this condition being caused by the presence of the train 8 on the track circuit section justin advance of signal 7, as is well understood by those skillcd'in this art. a

About opposite each of the far enough back of the insulating joints 2 so that the 'lKPlS of a train moving in the direction of traliic, that. is, of the-arrow A, will not have passed upon the two track rails in advance of a signal before a device on the vehiclc tobe hereilT after described, comes into proper co 0 i live relalion tl'lereu'ith,-

signals, but

in the direction ,each and point'u energized 21s is 111511 11519, coii just 11m the caution nal, b115 tho (:01! 11st bank 01: a clear signal. is energized. "H10 elm-11111 i11- vhuling :1 1301i 1111 if, 11111 1111 1'11 1 as fo iiows: one bmwh 11 1? 1211111 (1111.1'01111 1 1111111'111 01 l5, W110 "1 coil '17, 11m 1111-1: i8 wire 25 ,1 1,1111 Witch? 21 :11111 iftz 11:11111; {11,1

gixmi, 1111011111111 11110.1 11-11111 1:!

in 1165-1 11 of 31:11 6. 1

smvoal, hm 1111a, b1111 tho (13110 (11111 11 f 1.111 1 is; open 1 1; r0111 [ho $111111 R on 121111 211K I s -1111i 7 111111 that H11: (101 H 111111 2 of 170311 *1 :1 T, is 111. 111911011 duo (1o H11.

on 111112 sec-15011 11st .11

It is NOW appaia'ei over 1 1 (1 track way,

in the dii'oofiio'n of 1131111 ovor 21 11 (116%1'011'1agnsa'ti 41w:

signal which 1111i E mgonen nobio flux, but that tho same train W111 pa over-r111. elect 'omagnotio device 2112 si 6 and 3119190 mmagnetio device 1 :11; v '1, which 21m not genorahng a 'nmgmotio ii Let, ibnow be assumed that :1 ve 5011'; .1

resented ;'11o1*:111 \7 by oi? Fig. 21 11101 over U111 truckwgw iii11ssrato1i:by Fig. in the dkroction oi H111 1111711111 A. 11111 1191211. 151' 11111- plow-111011211111 p11 ovor 510 (1.1 nofiio dcv'ico EL U noor $11011 (111116.11 device 9 filust'mod 311 F 19;. 2, ms noctod (111.11%1 11 11111 11111111 11113";- genemtor 25, the. oirouit of which by hand swibc11,j S generates 11121 111 3619, i111 which finds 11s mosh appropl'iuto through the 1:111'1ina1ted ir'au core 2/? hung in any appyopriate olnsuitmk manner from. the vehicle 125 51 0111 {111011310 528 r4510 The agnetio flux Plowing $111111 core gonera'ses in coil .2 current 4 connected to a CilCu 1; 11 111021 12: c 4

01111319 ehiclo coruhuzi'iug 111 osiijflnmd and 13011. 111 to a, stem 31 on the end of which is a button which is spring pvcssod byvtho spring 33 to :the position hown, but if at U10 moment the (ore 27 passes the electromagnetic device 9, the button 32 is 110111;: 111 111 by the driver ]Cm-h of: 1111115: 00115 is conof the vehicle, 4.111011 the block vonneots the cm'ziacts 34 and 35., Under those oil-(111111- stains 11 (3011111111111 circuit is fOl'll'lQd 111111111- ing i110 coil 32.5) 11; the 011m :2? which (1111 11111 15; :19 011011141 (1-111: 17011111111111 of (31111 28, wire oi0ct1o1w1g11oi; 37, wirc 38, Contact 94:, ",k 30, coniuct 35, and wire 3!) back 10 115110 11111111. of Lhe (211.12 29. The 0111-- :rom flowing; in tho {11 (11 11'1111011, path enorgizos Hm oi ionnv 'noii bi, 2.1111 causes it 110 lift its m'ma'mro which 1 1111, 3 nnwcted to as -11. sum 111111 11 shaft causes ihnrvfix'n 1 moving, 1113 3 -1 51 1'1? mac, worm Wheel M. rof the w 111 1 .121 11 111031 2L pinion 56 1% train LGL m; :11) 101mm? in a oountevol "irocizion as viewed in 2 as soon 21$ b2li. 5'? starts to move iongitu E3; in thofljre 1tio11 of the 11115011 5.), b115, 1111: 7 21101? or h'lvev of "h s $611k driver until pointer 59 soured all of the time while the vehicle was traveling in the full clear block, this being due to the proportioniug between the diameter of the wheels of the vehicle, the train of mechanism connecting the axle with worm wheel 44, the size and number'oi teeth of pinion 56, rack 57, and pinion 58, and the particular positioning of pointer 59 upon the spindle to which pinion 58 is attached From the above it will be seen that atrain moving in the direction of the arrow A on the trackway as shown in Fig. would, if the driver pushed the button 32, at t e time he passed electro-magnetic device '9, receive an impulse which would cause worm 43 to be lifted allowing 44 to return to normal position and then worm dropping again into mesh with Worm wheel 44,

would cause Worm wheel l to rotate, cans-.- ing' through a train of mechanism, the no1nt-- or 59 to be moved counterclockwise, but the movement would not he observable by the hil reached the indication of.60 miles per hour, at which time the train would have reached signal 6, and would be about to enter a caution block,

that is, a block through which the speed of V the train must be gradually decreased so that the train would arrive at signal 7 at not more than 'a safe speed, say 0 miles per hour, or'10 miles r hour.

If the train, when it passes electromagnetic device 10, receives through its core 27 a magnetic fiux, and the driver is pushing hutton 32 at the proper time, then worm 48 would be raised out of mesh with worm wheel 44 and the same operations would take place as have just been described, but if no magnetic flux is generated by electromag netic device 10 when the train passes thereover, the worm 43 will remain in mesh with worm 414, and continue to turn the same in the direction of the arrmv l3, and the pointer 5!) would gradually move counter-clockwise and indicate the proper permissive speeds at which the train should be driven through the caution block, these speeds be ing indicated as gradually reducing to any given minimum, even to zero, but illustrated. in Fig. 2 as being reduced gradually to 10 miles per hour at which point the cut-away portion 61 of Worm wheel 44 comes beneath worm 43 and no further movement of worm wheel 44 is effected. Consequently, no further movement of pointer 59 is caused, so that the pointer never indicates less than a minimum permissible speed of, say, ten miles per hour. v I

Moving over the same graduated dial as the pointer 59 isa pointer 62, which pointer 62 is fixed to a pinion 63 moved by the toothed end of lever 6 1-, pivoted at 65, and

- niovablo in exact accordance with the actual speed at Wllllll the vcluclc 1S prmwcdlug. l)!!- ing; moved by 84, so lhat the hand 2 at all times indicates the actual speed of the vehicle. Consequently, if the driver keeps the slack hand (32 just al'icad, in a counterclockwise direction, of the pointer 59, while passing through the'caution block from signal 6 to signal 7, he is maintaining an actual speed of the train which is perfectly safe, and will enable him at all times to stop before arriving at thesignal 7 just in advance of which is located thcltrain 8.

Although the driver of a train is-supposed to at all times regulate the speed thereof, properly in accordance with indicalions transmitted to him, nevertheless it has found that he cannot always be dependccl upon to do this, either because, as in the extreme case he may suddenly die, or he may be inattentive or actually negligent, or even criminally careless, sothat although the pbinters 59 and 62 indicate toan engineman just exactly what he should do in order to be sale, it is necessary in addition to these to have other mechanisms which will actually stop the train if he fails to act in accordance with the indications presented to him. i

In order to effectuate this latter purpose, applicant has provided the electropneumatic valve 66, controlling in any usual way the venting of an air brake train pipe 67. mally this electropneumatic valve has a circuit closed therethrough, to maintain it energized and thereby prevent venting of the train pipe, The circuit for energizing valve 66 is as follows: one terminal of the battery 68, wire 69, contact 70, connector ?1, contact 72, wires 73 and 74, contact 75,

connector 76, contact 77, wires 78, 79, and

80, valve 66 and Wire 81 to the other terminal of the battery 68. This circuit normally maintains the valve 66 energized and so prevents venting of the train pipe and setting the brakes. There are, however, two

contacting devices in this circuit; one includes the connector 71 and'thc other the connector 76. The comicctor 71 is connect ed directly to the rod or bar 82, which bifurcated at its end and straddles the ro duced portion 83 of the movable slcovc 8iof a fly ball device indicated as a. whole by G. This fly ball device is driven from shaft 52, and is so arranged that as the speed of the vehicle increases the member 8+1- moves in the direction of the arrow D, so that rod 8 2-is also moved in the same direction, carrylng with it connector 71, and the cou- Norill)

lxacts 70 and 72 are of such length that they I ill) or the rack bur 57 in relation to contacts 75 and 77, thnt it spans these contacts 75 11ml 7? and electrically connects the some all of the time while the vehicle is travel,- ling throughout a full clean blocls: as from signal to signal 6. It will'thus be seen that if at any time the driver exceeds the fixed prcdetermined inaxii'ninn permissible speed, the clciiztropncuniutic valve (56 will be locncr id, because connector 71 wil be moved out of ccmtact with contacts 70 and 72 End also that all of the time the train. is traveling from signal 5 to signal 6 as illustrated. in Fig. 1, the circuit of the valve of through conunector 76 will he closeil, but at the .n'iomont the train our cs eig nul (5 the connector 76 moves out oi coniuct with (f()l=)&t(ftf-i 75 and 77, so that u n there are o'ihcr UXGQ'U'JS for closing the cu.-

cult between Wires '59 and 74 the valve 36 will be (lolniei'grlzeil. The otl'ier mean; for closing this circuit is the connector 8 illlnod to rack 30:11 57, and so attached just before 76 moves out of contact- ;h 15 and Y7, 85 moves into contact with coi'atncts 86 can 87, and this as at the iustni'it the train evident by an, i1

if the time while eon ri in null 77 lb: and 90 i i such ived througl'i battery i en to iniicute that 76 has L RUM of contact with T5 and runl 85 has not n'ioveil into o and 87, or it in that the vehicl full elm 01 in q soon howev vout w" ith and 'nto r 1 with 93 and SW,

" the bigmil suchxi'oi' XL) 95 li htccl by T'.1S( ii olf lie tulcen to and must i 2111 si i. '1 g'lIi i n i'euuce s" the ehic pziuiscfs signal 6, icviug ti A and .m' it magnetic flux f!!! cl-ecnetio levies 3Q, it pro (is, the moves gradually oeuuter--ci0ol mo the. iuembor 85 u'ioveo in the 1 After it certain ed by the train under. those of? of th i distance trnrvc eondiizim the nienilgieir 85 will pm. continua 8", uncl onto contact 97. and. will result in ilcenei'gizing the- Vzilvc 66 unless in the ineuntii'no a button, 98 has been u'csmuii by the driver of the vehicle This is so because when the circuit for the valve 66 was opened at connector 76, it was closed by connector 85, so that current flowed through the valve (36 in a circuit as follows: one terminal of the battery- 68, wire 81, valve (36, wires 80 79 and 99, contnct 87, connector 85 contact 86, wires 100 nn l 73, contact 72, connector 71, contact 70 mini wire 69 back no the other terminal of the battery 68.

The current flowing in the above-traced path nminluini; the oncrgization of valve 66 u'l'tcif thc breaking of the connection lmtween T and '77, but when cmn'icctor 85 moves out of contact with contact SL- the last traced circuit i.-: then broken, and the Valve 66 .\'()ill(l l)(? ilccnergixed another circuit were not ivlillttl. This other circuit is formed by the contact of 85 with contact 97 and by the pushing of uitton 98, which causes a connection between wires L, nnii 102, so that if 545 is cont-act with 86 and 97, and button on has been pushed, it circuit for valve 66 is oi-mull as follows: one terminal of; the butlery 58., 81., valve Gu -wires 80, 10%, 105, 10%;, 10? cool 1.01, connector 103, wiie 102, contact 9'7 CHIQBCtQP/S l contact 8 wires W0 and 7 7 contact connector 71, contact T0 21ml wire to the other terminal oi the battery '88. Current flowing in 1 he nbovetraced path maintains the encrgization of valve (56. SlKHllil be nitcd however that it'filll l in"? traced (.lcpcmls for its COD ilnuity both upon S43 QOIlHW'ii-lilg 86 and ill, and upon 103 c zine-cling 1191 211ml 102. The c eation between 86 and 97 by is made inevitable izylhc forward movement of the i 4. null a connection which corresponds with, the i n the permissible inol o button 98 must be menwl hy' the driver, and this fact vow to maintain his obser '2 :ion of the lWl pointer 59, beuit Winter in lia'zntcs just a: litv miles per hour, it iudi.

3: or 85 is about to move mi {:4 not 87 to contain 9i, and that unm 5.33 pm i i the valve (iii will. he-

illl'll izmi, Zlhcity for the in ulntin;: button Q8 also obliged w to maintain i /etch of the actual Si Z, been use the button 103 as designated in Fig. 2 is shown as a metallic aemher which, upon being depressed, one, 1 8, of two adjacent similar contc s, to which wires 101 ant 102 connected.

Between the plate 111 and the lever 121 is a resilient connection 123, comprising a member 139 connected to lever 121 and a. member 140 connected to plate 1.11. Each of these members 139 and 140 have outstanding projections, as 141 and 149-,on 139, and 143 and 144- on 140; and between these outstanding projections is an expanded spring 145 of such size that it will transmit motion from lever 121 to plate 111, under ordinary conditions without either compressing or extending, but if the actual speed of the train is increased after a button as 98 has been depressed so that a plunger as 1.10 rests in a slot 112 of the plate 111, then when due to an increase in speed the plate 11.1 causes the end of the slot 112 to contact with the plunge as 110, the resilient connection is such that relative moven'ic'nt is allowed be-- tween lever 121 and plate 111, so as not to shear the plunger 110, I

The parts are so propmrtioncd as shown in Fig. 2 that when connector reaches and passes the extreme upper end of 132 as viewed in 2, the cut-away portion. (51

of the wornr wheel 4e is underneath the -worm L3, so that no further movement of 85 takes place and the train may proceed indefinitely at not more than, say, ten miles per hour, which permissible speed, as he tore pointed out, will continuously indirated by the red hand 59, and will be al lowed by reason of contacts 120 and 137.

After the mechanism. on a vehicle as shown by Fig. 2 has gone through the operations as herein before described, the rod pointer 59 will constantly indicate a permissible speed oi ten miles per hour until he vehicle passes over an electromagnetic device in the trackway as 9 which will cause a magnetic flux through the iron core 27 on the vehicle. At that time as hereinbetoro described the elcctroimm net 27 will be cnergizcd, worm 1;?) will he lifted, worm wheel M will return to its initial position shown in Fig. 2, and the rack bar 57 will alsore turn to its initial position as shown in Fig. 2. and by so doing will move the member 146 to the position as shown in Fig, 2, so that tho wedged mcmhcrs 147, as perhaps best shown in Fig. 3, will contact with the upturned ends, as 1. 18, of the rodsgas 14S), attached to plunger 124, andwili move the rods, as 14-9, and plunger 124 to the left as viewed in Fig. 3, so that the "plunger 12-1 will be withdrawn from the cavity 125 in the plunger 110 and then the spring 150 will force the button 98 and its attached parts to the original nndcpressed position. This same action will take place with all menses of the buttons 11'? to 115 incmsive, so that they will. all returnto normal undepressed position. d

From the above description it will be seen that applicant has provided a train control device which is truly semi-automatic in its operation, because if a vehicle equipped with a system in accordance with applicants-invention, passes a full clear signal, it is necessary for the driver to actually perform a manual operation or else the apparatus will so act asto cause and impose a constantly decreasing permissible speed, so that with a system constructed in accordance, with applicants invention, if a driver should fall dead just before reaching aclear signal, a gradually decreasing permissible speed will .be immediately imposed upon the vehicle and it would not proceed perhapspast a dozen clear signals before it would he brought to a stop by reason of encountering a danger signal. This is very important because signals as a rule only indicate the existence oi temporary hazards, that is, the existence or movahie trains on the trackway ahead, but there are many permanent hazards on the traclrway the existence of which not reflected by the signals or by the track circuits, and these permanent hazards, such as curves andgradcs, require for safe operation a maximum permissible speed sometimes very much lower than the maximum permissible speed allowed at other points on the roadway, so that it is essential that a train should be brought down in speed when passing these permanent hazards even though the signal indicates full clear. This applicants system provides for this, because as soon as the driver becomes incapacitated or fails to perform a simple manual operation, the train has imposed upon it a gradually decreasing maximum permissible speed even under full clear conditions, so that for this reason applicant has denominated his system a semi-auton'iatic system because it requires the cooperation both of the driver and the trackway device to pass even a full clear signal without having a gradually decreasing maximum permissible speed imposed. v

It is also apparent that in accordance with ap1' licauts system,- a'fter a vchicle -has entered what has been called a caution block or section in which a gradually "decreasing maximum permissible speed should' bc im posed, that manual operations of the driver are required after the train has travcrscd successive distances alongthe trackwa'y, so that the driver must not only graduallyreduce the speed of its-train in accordance with the predetermined curve of speeds, but he must also perform certain manual operations in order to proceed continuously even if he has reduced his speed to the proper amount, so that again for this reason also lit) menses applicant has denominated nis system a semi-automatic system.

Applicant, of course, does not intend to restrict the positioning of the traclrwey device, as 9, to the exact positions, as shown, as the positioning of these devices would de pend upon the layout of tile signals and track. but whatever the positioning it must be such that it Will properly co-operate with applicants train device, so that a train will always be brought to a minimum low speed or stopped before entering an occupied track section. lilor does applicant intend to restrict the use of track devices, 9, to positions only at or closely adjacent to signals; Nor does applicant mean to convey the impression that the ordinary type of signal is at all necessary with his invention.

'silion circuit controller and a Although I have particularly des heal the construction of one physical emocc ment of my invention and explained the operation and principle thereof, nevertheless I dee'ir to have it understood that the form selected.

is merely illustrative but does not exhaust.

the possible physical embodiments of the idea ofmean's underlying my invention.

Vlfhat I claim as new and desir to secure by Letters Patent of the United States is: ll ln a semi-automatic train control de vice, in combination; a vehicle; a roadway; means on the vehicle including manually operable means cooperating with means on theroadway for allowing the vehicle to travel at not above a predetermined maKi rice. in combination: a vehicle; a roadway; means on the vehicle, including manually operable means, coopera ing with incans'on the roadway TiOlQllHllCZltliLfil a maximum permissible speed torthe vehicle, a gradually decreasing permissible speed and a pennies-i ble miniinum speed.

3. ln a scnii-autonnitic train control, in combination; a vehicle; a roadway; means on the roadway for generating a magnetic flux; a partial circuit on the vehicle'includinc a manually operable biased to open poeiving coil and an elcctromagnet whereby a current is generated in the partial circuit toe electro-magnct energized when the receiving coil passes over the roadway means When generating a magnetic flux ii the circuit controller is being operated manually; an arms-- ture controlled by the electronagnet and arlnature control der to proceed at gradually reducing speeds down to a permissible minimum speed and to then proceed indefinitely at such minimuzn speed Without taking further action.

5. in a semi-automatic train control in combination: a vehicle; a roadwa a vehicle" control device on the vehicle; nieanson the vehicle for causing said device to operate todecrease the speed the vehicle if the speed exceeds a predetermined maximum; means for causing said device to operate to decrease the speed of the vehicle if the vehicle exceeds certain predetermined sub-maxinuiim speeds including devices which must be menually operated after certain predetermined lengths of travel of the vehicle and means for preventing the operation of said device to decrease the speed of thevehicle regard less of its length of travel if the speed of the vehicle is below a predetermined minimum.

6. The method of train control which consists in ohliging the train driver upon approaching a danger point to take action at regularly recurring substantially short intervals in order to proceed at gradually reducing spcedsdown to a permissible mininuunspeod and to then proceed indefinitely at such minimum speed Without taking further action.

7. In a semi-automatic train control .in combination: a vehicle; a roadway; a vehiclc control device on the vehicle; means for causingsaid device to operate to decrease the speed of the vehicle if the vehicle eX coeds certain predetermined sub-maximum speeds, including devices which must be manually operated after certain predetermined lengths of travel of the vehicle and means for preventing the operation of said device to decrease the speed of the vehicle regardless ot' its lcnglh o'f travcl thereafter if the speed of the vehicle is below a pre determined minimum.

LYlilAN n. cones. 

